1. Field of the Invention
The present invention relates to a shaft-and-yoke coupling structure to be applied to universal joints.
2. Discussion of Prior Art
The present invention relates to a shaft-and-yoke coupling structure to be applied to universal joints.
Conventionally, for example, among shaft-and-yoke coupling structures of steering joints, there has been provided one in which after a shaft is slid axially so as to be inserted into a yoke, a bolt radially inserted into the yoke is tightened so that the yoke and the shaft are coupled together.
Another shaft-and-yoke coupling structure is that, as shown in FIG. 7, a shaft 71 is slid radially into a yoke 72 perpendicularly to the axis so as to be inserted into the yoke 72.
However, in the latter coupling structure, a tightening bolt (not shown) is inserted into bolt holes 73, 75 of the yoke 72 after the shaft 71 is fitted into the yoke 72. Therefore, the worker has to hold the fitted state of the shaft 71 and the yoke 72 until this bolt is tightened up, which causes a disadvantage of poor workability.
There is also another disadvantage that the shaft 71 and the yoke 72 may be axially decentered or inclined each other before the bolt is tightened up.
Therefore, an object of the present invention is to provide a shaft-and-yoke coupling structure which is superior in workability and capable of correct assembling.
In order to achieve the above object, the invention provides a shaft-and-yoke coupling structure comprising: a yoke having a shaft insertion portion which is cross-sectionally U-shaped and end portions of which have bolt receiving portions for a bolt to be inserted; a shaft to be inserted into the shaft insertion portion; an elastic presser plate covering an outer surface of the shaft insertion portion and having at least one claw bent toward an inner surface of the shaft insertion portion, wherein the shaft inserted into the shaft insertion portion is restricted by the claw.
According to this invention, since the claws of the presser plate restrict the shaft inserted into the shaft insertion portion, the shaft can be temporarily secured to the yoke by the presser plate, making it easier for the worker to perform the bolting work. Therefore, according to this invention, it is possible to obtain a shaft-and-yoke coupling structure which is superior in workability and capable of correct assembling.
In an embodiment of the invention, the presser plate is formed in such a way that a wedge-shaped gap is formed between the presser plate and the outer surface of the shaft insertion portion so that, by fastening the presser plate with the bolt inserted into the bolt receiving portion, the presser plate is inwardly flexed to press the shaft with the claw.
According to this embodiment, since the claws of the presser plate press the shaft by making use of a force of tightening the presser plate with the bolt, the shaft and the yoke can be prevented from being axially decentered. Also, after the bolt tightening, the shaft can be securely fixed to the yoke by the claws of the presser plate. Therefore, even if any prying force occurs after the bolt tightening, the shaft and the yoke can be prevented from being axially decentered.